Wow, your lens is so fast, they are so clear. We did also some feeding frenzy in one of Thailand's tour north of Bangkok but i forgot the place. I remember it was near a Monastery where catching fish is not allowed, so they are so big already. Tourists on boats like us fed them with loaves of bread and it's amazing how they were able to finish it so quickly. JM, you are already very near us, please check my post about Underground River, haha!